Since composite materials, particularly, fiber reinforced plastics containing reinforced fibers such as carbon fibers solidified with a resin are light in weight and have made of high strength and high elasticity, they are frequently used for aerospace, sports, and leisure goods. They have also been used more widely for general industries such as automobiles in the recent years, and are expected to become more important materials in the future.
To further increase the use of fiber reinforced plastics in general industrial fields, it is important to reduce the price. Accordingly, it is important to manufacture the fiber reinforced plastics at low cost and at high productivity and therefore it is desired to establish a method for manufacturing them.
A forming method using a multiaxis multilayer reinforced sheet is expected as a low-cost and high-productivity manufacturing method. A method of laminating several sheets in which reinforced fibers are oriented in one direction at a predetermined angle is low in productivity because it takes much time and labor. However, laminating one or several multiaxis multilayer reinforced sheets containing fibers oriented at a predetermined angle in a given thickness can provide high-pseudoisotropy products.
Of course, it is necessary to produce high-quality and high-productivity multiaxis multilayer reinforced sheets. In other words, low-quality and low-productivity multiaxis multilayer reinforced sheets cannot provide low-cost final products. It is therefore important to produce high-quality and high-productivity multiaxis multilayer reinforced sheets.
Various apparatuses and methods for manufacturing multiaxis multilayer reinforced sheets have been proposed. Examples of the apparatuses and methods for manufacturing multiaxis multilayer reinforced sheets with high productivity include an apparatus and a method of inserting wide sheets at a predetermined angle and laminating them: for example, a first method in which a plurality of fiber reinforced sheets are wound in a spiral manner at a predetermined angle (e.g., JP-A-2003-221771) and a second method in which fiber reinforced sheets with different angles are laminated in sequence on a fiber reinforced sheet running on a pin tenter (e.g., JP-T-2001-516406) (the term “JP-T” as used herein means a published Japanese translation of a PCT application).
By the first method disclosed in JP-A-2003-221771, when the sheets are laminated at any angle (θ°), lamination at a symmetric angle (−θ°) occurs without exception and only sheets with the same thickness can be laminated. This makes it difficult to provide multiaxis multilayer reinforced sheets in which desired-thickness sheets are laminated at a desired angle and order.
In the second method, in general, a roll wound with a fiber reinforced sheet is disposed by the side of a pin tenter, from which an end of the fiber reinforced sheet is drawn out and cut in a predetermined width, and mounted to the spikes on the pin tenter.
However, this needs the time to draw the fiber reinforced sheet from the roll, thus taking much time to manufacture.
To solve the above problems, JP-T-2001-516406 discloses a method in which a plurality of holding heads movable along a closed loop path are disposed, an adhesive is applied to ends of the holding heads and the fiber reinforced sheet is bonded to the holding heads with the adhesive whereby the fiber reinforced sheet is drawn out, as shown in FIGS. 12 and 13. This method can reduce the drawing time because of the plurality of holding heads.
However, the holding heads need to be applied with an adhesive to draw one fiber reinforced sheet, and when the adhesive strength of the adhesive is low, the fiber reinforced sheet can come off the holding heads while drawing the fiber reinforced sheet.